Question

Exercitiul 2...........

Answer 1

se formeaza triunghiuri si piramide asemenea (Thales)
raportul inaltimilor=4/6=2/3 =raportulde asemanare
raportul ariilor bazelor =(2/3)²=4/9, patratul raportuluide asemanare

arie mica/arie mare=4/9
arie mare= 12²√3/4=144√3/4 cm²
arie mica=(4/9)*arie mare=(4/9)*144√3/4=144√3/9=16√3cm²



Volum piramida mica=(2/3)³ *Vpiramida mare= (8/27) *Vpiramida mare
cubul raportului de asemanare
atunci
 V trunchi de piramida= Vpiramida mare- V piramida mica=
=Vpiramida mare (1-8/27)=(19/27)* V piramida mare=
= (19/27) *(VO/3)*L²√3/4

(19/27)*(6/3)*12²√3/4=(19/27)*2*36√3=(8*19√3)/3cm³=(152√3)/3cm³